Block-signal system for railways.



No. 791.907. PATENTED JUNE 6, 1905. C. HOLTMANN.

BLOCK SIGNAL SYSTEM FOR RAILWAYS.

APPLICATION FILED APE. 6,1904.

4 SHEETS-SHEET l.

. PATENTED JUNE 6, 1905.

C. HOLTMANN.

BLOCK SIGNAL SYSTEM FOR RAILWAYS.

APPLICATION FILED APR. 6,1904.

4 SHEETS-SHEET 2 Milli-"Ill No. 791,907. 'PATENTBD JUNE 6, 1905.

c. HOLTMANN.

BLOCK SIGNAL SYSTEM FOR RAILWAYS.

APPLICATION FILED APR. 6.1904.

4 SHEETS-SHEBT 3,

Q/Vitvwoowa G. HOLTMANN.

PATENTED JUNE 6, 1905.

BLOCK SIGNAL SYSTEM FOR RAILWAYS.

APPLIOATION FILED APE. 6.1904.

4 SHEETS-SHEET 4.

31mm for UNITED STATES Patented June 6, 1905.

PATENT OEEicE.

BLOCK-SIGNAL SYSTEM FOR RAILWAYS.

SPECIFICATION forming part of Letters Patent No. 791,907, dated June 6,1905.

Application filed April 6, 1904- Serial No. 202.112.

[0 aZZ 1077 0772, it may concern;

Be it known that I, CARL HOLTMANN, a citizen of the United States,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented new and useful Improvements in Block-SignalSystems for Railways, of which the following is a specification.

This invention relates to a block-signal system for railways, theprimary object of the invention being to provide mechanism actuatedmechanically and electrically for the purpose of indicating eithervisibly or audibly, or both, to an engineer in the cab of a locomotiveor an agent located in a signal-tower or railway-station that an engineor train is 00- cupying a certain point or an approximate point on theroad or that another engine or train is located at a certain orapproximate point on the road, the devices hereinafter describedenabling an engineer to ascertain when another engine or train isoccupying an adjoining block, thus reducing to a minimum the chances ofcollision.

It is also an object of the present invention to provide novel meanswhereby the air-brakes of a train may be automatically thrown intooperation when two locomotives or trains approach within a certaindistance of each other, also to notify an agent in a signal-tower orstation when a locomotive or train has arrived at a certain point, andto place electrical transmitters in the engine-cab and station or towerin electrical communieationwith each other for the purpose of enablingthe operators to communicate.

One of the principal objects of the present invention is to providemeans operating automatically by means of an open or closed circuit torelease and throw the throttle-lever of the engine and simultaneouslysignal the engineer either audibly or visibly, or both, the approach oftwo trains within a certain distance of each other, thus operatingautomatically through the connections hereinafter described to throttlethe engine and apply the air-brakes for bringing one or both trains to astop.

l/Vith the above and other objects in view, the nature of which willmore fully appear as the description proceeds, the invention consists inthe novel construction, combination, and arrangement of parts, ashereinafter fully described, illustrated, and claimed.

In the accompanying drawings, Figure 1 is a diagrammatic plan viewshowing a few adjoining blocks of a railway system, illustrating thetrack-wiring, the air-brake connections, the signaling devices, and theelectrical connections and relays. Fig. 2 is an enlarged sectionalelevation of the air-brake-oontrolling mechanism and throttle-actuatingand signal-operating devices. Fig. 3 is an enlarged sectional view ofthe engine-relay. Fig. 4: is a front elevation of the same, showing theswitch mechanism. Fig. 5 is a plan view illustrating the manner ofinsulating the rails and blocks. Fig. 6 is a detail view of therack-and-pinion movement for operating the signal-lantern within the cabof a locomotive. Fig. 7 is an elevation of an engine and tender, showingthe means for insulating the same. Fig. 8 is an enlarged detailsectional view of the draft or coupling link between the engine andtender. Fig. 9 is a diagrammatic plan view showing a portion of thetrackwiring.

Like reference characters designate corresponding parts in all figuresof the drawings.

Referring to the drawings, and particularly to Figs. 1 and 2, ldesignates the storage tank or reservoir in which the compressed air isstored from the engine, and 2 designates the air-supply pipe leadingfrom the tank or reservoir l to the valve which controls the airbrakesystem. At a suitable point in said pipe and arranged within the cab isan airvalve casing 8, in which is arranged an airvalve having associatedtherewith a magnet and armature, by means of which the valve is openedto admit air to a cylinder 4:, in which is arranged athrottle-controlling piston 5. In order that the construction andoperation of the valve in the casing 3 may be understood beforeproceeding further, attention is called to the construction of awhistle-controlling valve 6, which is shown in section in Fig. 2 andwhich corresponds in construction with the valve at the point 3. It willbe observed that the valve 6 is conical and that it ICO controls thepassage between the sections 7 of the air-supply pipe, which leads tothe pneumatic whistle 8. The valve 6 is normally held seated by means ofa coiled spring 9, arranged in a cavity 10 in the valve-easing and heldin place by means of a removable screw-cap 11. The stem 12 of the valvepasses slidingly through the core 13 of an electromagnet 14 and isprovided upon its outer end with an armature 15, located normally ashort distance from the magnet 14, so that when the magnet is energizedthe armature 15 is attracted thereto, thus unseating the valve 6 andpermitting the air to flow through the pipe 7 and sound the whistle.

In the manner above described the armature 16 of the valve within thecasing 3 is attracted by the magnet 17, so as to unseat said valve andallow the air to pass through the supply-pipe 2 into the cylinder 4,where it acts to throw the piston 5 back against the tension of a spring18, which is coiled around the rod 19 of the piston 5 until said pistonhas passed beyond the entrance-point of a pipe 20, which leads from thecylinder 4 to another cylinder 21. The stem 19 is extended so as to havethe end thereof arranged close to the throttle-lever 22 of the engine,and at its extremity the rod 19 is provided with a wedge or cam 23 andalso with a shoulder 24 at the inner end of the wedge or earn, asclearly shown in Fig. 2. As the rod 19 is thrust toward thethrottle-lever the cam engages beneath a pin 25 on the slidingthumb-latch 26 of the throttle-lever, thus lifting the latch out ofengagement with the segmental raek 27. The shoulder 24 then strikesagainst the pin 25 and in the further movement of the rod 19 throws thethrottle-lever 22, so as to shutoff steam. The rod 19 is also toothedalongone side, as at 28, to form a rackbar, as shown in the detail viewFig. 6, the said rack-bar meshing with and d rivinga pinion 29, which isfast on the shaft 30 of a signal-lantern 31, so that as the rod 19 actson the throttlelever it also acts through the medium of therack-and-pinion engagement described to turn the lantern 31 until thelight is visible to and attracts the attention of the engineer, who isthus advised of the throwing of the throttlelever and the shutting offof the steam. WVithin the cylinder 21 is mounted a valvecontrollingpiston 32, the piston-rod 33 thereof having connected therewith arelief-valve 34, provided with an angular air-passage and a straightair-passage 36. The valve 34 slides within a valve-casing 37, which isintroduced in a pipe 38, leading from the main airsupply pipe 2 upwardto the usual engineers valve 39, to which the train-pipe 40, whichcontrols the air-brakes on the tender and cars, is connected, as shownin Fig. 2. Normally the air-passage 36 is in line with the oppositeportions of the pipe 38, so as to allow the excess of pressure in thepipe 2 and reservoir 1 to overcome the lesser pressure in the train-pipe40. \Nhen the piston 32 is driven in the direction of the pipe 38, theair-passage 36 is moved out of communication with the pipe 38 and theangular passage 34 is brought into communication with the upper portionof the pipe 38 and also into communication with a short connection 41,which leads to the usual governor 42, by means of which the air-pressurein the train-pipe is released in the operation of applying the brakes.The piston 32 is normally held in the position shown in Fig. 2 by meansof a coiled spring 43, which encircles the stem 44 of the valve, thesaid stem being preferably squared or keyed so as to prevent the turningof the valve 34 within the valve-casing, thereby insuring theregistering of the air-passages 35 and 36 with the pipe 38 and theconnection 41 leading to the governor.

45 represents a cut-off located in the pipe 38, while 46 designates anair-pressure gage connected by a suitable pipe 47 with the engineersvalve 39 and train-pipe 40.

From the foregoing description it will be observed that when the valve 3is opened by the electrical connections hereinafter to be described thethrottle-lever is operated so as to automatically shut off the steam inthe engine. The signal-lantern 31 is operated to notify the engineer.and the relief-valve of the air-brake mechanism is moved so as to cut06? the excessive pressure from the storage tank or reservoir andrelieve the pressure in the trainpipe, and thus apply the brakes, theseveral steps enumerated being accomplished automatically without anyattention on the part of the engineer. The electrical applianceshereinafter described also operate the whistle-controlling valve 6, andthus give an audible alarm.

Before entering upon a description of the wiring system used inconnection with the track it may be noted that the engine or 10-comotive (indicated at 48) is insulated from the tender 49 by means of aco u pling-link 50, composed of sections, as shown in Fig. 8, whichsections are insulated from each other, as shown at 51, and firmlyconnected by bolts 52 or their equivalents. The body of the tender 49 isalso insulated from the truck-wheels and axles, as shown at 53, theobject in insulating the parts hereinabove described being to allow onepart of the current to flow between the rails through one of the axlesof the locomotive, while another or return portion of the current flowsthrough one of the axles of the tender when the locomotive and thetender occupy positions on opposite sides of the insulation in the railsbetween the blocks or between the blocks and one of the short railshereinafter particularly described.

Referring now to Fig. 1, I have therein illustrated a portion of arailway in which different blocks a, I), 0, (Z, a, and f are shown, the

said blocks being insulated from each other, as

IIC

shown at 54. In certain blocks, and preferably every alternate block,short rails g, it, and j are insulated from the remainder of the block,as shown at 55. Alternate blocks are also placed in electricalcommunication with each other by means of track-batteries 56, 57, and 58and connecting-wires 59, by means of which a continuous current flowsbetween the rails of said sections or blocks until the current is brokenby a locomotive and tender or train, as will hereinafter appear.Suitable relays 60, 61, 62, 63, and 64 are arranged along the track andsuitably connected by wiring with the rails of the several blocks, whilethe engine-relay 65 is arranged in the locomotivecab and connected bywires 66 and 67 with the engine and tender, as shown at the left hand ofFig. 1, an engine-battery 68 being interposed at a suitable point in thecircuit 66 67. The armature 69 is normally held against the magnet 65until the circuit is broken, and upon the breakage of the circuit an arm7 O, which carries the armature 69, moves away from the magnet 65 and bymeans of a terminal hook 71 thereon engages and interlocks with apivoted catch 72, provided with a projecting arm or linger 7 3, whichpasses through an opening in the relay box or case 7 1, so as -to beacted upon by a hand-operated switchlever 75 within reach of theengineer, the catch 72 being backed by a spring 76, which sustains thearm or finger 3 in the path of the switch-lever 75, as shown in Figs. 3and 4:. Connected with the arm 70 is a circuit-wire 77, which leadsthrough an engine-battery 78 to the signal-switch '75, adjustable to aseries of buttons 80, 81, 82, and 83 on the switchboard, separate wiresfrom which lead to suitable alarm devices to be hereinafter described,while the return-wires from said alarm devices conncct with a commonreturn-wire 84, which connects with the catch 72. 85 designates atest-switch connected by wires 86, which cut into the circuit-wires 77and 84;, just described. From the switch-button a wire 87 leads to anelectric bell 88 and returns by wire 89 to the common return-wire 84:.Another wire, 90, leads from button 81 to an elec tric light 91 andreturns by wire 92 to the common return-wire 8 1. From button 82 a wire93 leads to the whistle-controlling valve 6 andreturns through wire 94to a common return-wire 84:. From the button 83 a wire 95 leads to themain air-valve 96 and returns through wire 97 to the common return-wire8th. Therefore by adjusting the signal-switch lever 75 to the buttons80, 81, 82, and 83 any one of the several alarms and valves may bethrown into circuit and operated. The switchlever 75 usually remains incontact with the button 82, so as to sound the whistle.- The engineerthen moves the lever 75 to the button 88, so that the brakes may bethrown automatically into operation. In order to sound the whistle, thearm 70 of the engine-relay must necessarily be released, whereupon it isengaged and held by the catch 72. Now as the engineer moves theswitch-lever 75 toward the button 83 said lever operates on the arm orfinger 73, thereby rocking the catch 72 and disengaging the arm 7 O,which permits the armature 69 to be attracted by the magnet 65, thusagain closing the interrupted circuit. It will thus be observed that thearm 7 O is automatically released in the shifting of the switchlever.The test-switch is provided in order that the engineer may at any timetest the engine-battery 78 and observe Whether the circuit is operative.

In order to explain the operation of the electrical connections of thesignaling system, it will be supposed that a train occupies theleft-hand end of the track, (shown in Fig. 1,) with the locomotive onthe short rail 3 and the tender on the block a. Suppose also a trainoccupies one of the succeeding blocks for example, the block d. As oneof the axles of the locomotive or tender will shortcircuit the currentwhich flows through said block, the current will be interrupted, thusallowing the armature 98 to drop away from the relay-magnet 62, breakingthe current passing through the wires 99 and 100. This also interruptsthe current passing through the wires 66 and 67, leading to theengine-relay 65, the result being that 'the arm 70 is released andengaged by the catch 72, the whistle 8 being at the same time sounded.The engineer now throws the switch-lever 75 to the button 83, and as thetrain passes onto the block b, if there is still danger aheador, inother words, if the other train still occupies the block (Zthe currentgenerated by the engine-battery 78 will operate the valve 6 and by themechanism hereinabove particularly described throw the air-brakes intooperation. The electrical connections between the block 0 and theshort-rail section g and block a are the same as those just described,so that in case trains or locomotives or tenders occupy any of saidblocks the relays will be deenergized and the circuit broken, so as torelease the arm 70 and establish a circuit in the wires 77 and 84: orany of the subsidiary circuits related thereto. It will thus be seenthat where two trains approach Within a predetermined distance of eachother the signaling devices, engine-throttling mechanism, and air-brakeapparatus will be automatically thrown into operation withoutnecessitating any action on the part of the engineer.

In Fig. 9 I have illustrated an auxiliary system by means of which thelocation of a train may be indicated in a signal tower or station andtwo telegraphic instruments, one in the station and one on the train, beplaced in communication. At certain locations in the road-bed a shortinsulated rail 101 is introduced adjacent to the insulation 102 betweenadjoining blocks. Now when the wheels 103 of the engine rest on oneblock and the wheels 104-. of the truck rest on the adjoining block onthe short rail 101 the current will pass rail 105, through wire 106 andbattery 107, to a bell 108 and return through Wire 109 to rail 110.Before leaving the section or block 7r one of the axles of the trainwill close the circuit leading to the bell 108, and thus sound the sameand thus notify the man in the signal tower or station a. After thetrain reaches the position shown in Fig. 9 the current will pass throughthe wires 111, telegraphic instrument 112, engine-bell 113, and wire 114to the rails and therefrom through the wire 115 to wire 106, throughtelegraphic instruments 116, and back through return-wire 117 to therails, thus enabling operators in the engine and tower or station tocommunicate with each other. The arrangement shown in Fig. 9 isparticularly valuable where it is necessary to detain a train until somecontingency happens, after which the train may be notified to proceedwhen the track is clear.

Under the track-wiring system illustrated and described thetrack-circuit will be broken in case of a broken rail, an open switch, abroken wire, an open drawbridge, or in case of derailment and the like,the effect being exactly the same as the presence of a train, which actsby placing the rails in communication to break the circuit.

Having thus described the invention, what is claimed as new is 1. Thecombination with an air-brake system, of a throttle-valve lever providedwith a sliding latch having a pin or projection, a cylinder, a pistontherein, a piston-rod provided with a cam or wedge to engage said pin orprojection and retract the latch and with a shoulder at the inner end ofsaid cam or wedge to engage and throw the lever, andelectrically-controlled means for admitting air to said cylinder.

2. The combination with an air-brake system, and a throttle-lever, of apressure-valve located in said system, a cylinder and piston operativelyassociated therewith, a second cylinder and piston operativelyassociated with the throttle-lever and in communication with thefirst-named cylinder, said second cylinder being provided with anair-escape port directly controlled by the piston therein, and anelectrically-controlled valve which admits air to one cylinder, movesthe piston thereof so as to admit air to the other cylinder, said pistonpermitting air to pass from the firstnamcd to the second cylinder bymovement beyond the said port to uncover the same, whereby thethrottle-lever and pressure-valve are simultaneously operated to cut offsteam from the engine and set the brakes.

3. The combination with an air-brake system and a pressure-relief valvearranged therein, of a throttle-valve, a cylinder having an escape-port,a piston therein adapted to operate said throttle-valve and to directlycontrol said port, a second cylinder in communication through said portwith the first-named cylinder, a piston therein controlled by pressuresupplied through said port from the firstnamed cylinder and controllingsaid reliefvalve, a valve for admitting air to the firstnamed cylinder,a normally closed circuit car ried by the engine, a normally opencircuit, including said last-mentioned valve and arranged to be closedon breaking the closed circuit, and a track-circuit arranged to beshort-circuited by the passage of a train to break said closed circuit.

1. The combination with an air-brake system, of a cylinder, a pistontherein, a pistonrod havinga rack-face, a movable signal-lamp having apinion engagement with the rackface, and an electrically-controlledvalve for admitting air to said cylinder.

5. The combination with an air-brake system, of a cylinder, a pistontherein, a pistonrod, a signal-lamp geared to the piston-rod andoperable thereby, and an electrically-controlled valve for admitting airto said cylinder.

6. The combination with an air-brake system, and a throttle-lever, ofacylinder, a piston therein, a signal-lamp, a piston-rod operativelyrelated to the throttle-lever and lamp so as to simultaneously actthereon for the purpose specified, and an electricallycontrolled valvefor admitting air to said cylinder.

7. The combination with an air-brake system, a throttle-lever, and apneumatic whistle, of a cylinder, a piston, a piston-rod operativelyrelated to the throttle-lever, and electrically-controlled valves forsimultaneously admitting air to said cylinder, and the whistle.

8. In a signal system of the character described, a normally closedtrack-circuit, a normally open engine-circuit, a controller between saidcircuits comprising an electromagnet and armature, means for lockingsaid armature when the magnet is deenergized and the armature releasedto close the engine-circuit, a signal, air-brake mechanism, a switch fornormally connecting the said signal with the engine-circuit and adaptedto connect the air-brake mechanism with said circuit, and means forautomatically throwing said locking means out of operation when saidswitch is moved to disconnect the signal from and connect the air-brakemechanism with the engine-circuit.

In testimony whereof I affix my signature in presence of two witnesses.

CARL HOLTMANN.

lVitnesses:

N ELLIE G. REYNOLDS, BERNARD P. VAsIIoN.

